tag.con commit Merge branch 'vd/doc-unpack-objects' (ea06592)
   1#include "cache.h"
   2#include "tag.h"
   3#include "commit.h"
   4#include "tree.h"
   5#include "blob.h"
   6
   7#define PGP_SIGNATURE "-----BEGIN PGP SIGNATURE-----"
   8#define PGP_MESSAGE "-----BEGIN PGP MESSAGE-----"
   9
  10const char *tag_type = "tag";
  11
  12struct object *deref_tag(struct object *o, const char *warn, int warnlen)
  13{
  14        while (o && o->type == OBJ_TAG)
  15                if (((struct tag *)o)->tagged)
  16                        o = parse_object(((struct tag *)o)->tagged->sha1);
  17                else
  18                        o = NULL;
  19        if (!o && warn) {
  20                if (!warnlen)
  21                        warnlen = strlen(warn);
  22                error("missing object referenced by '%.*s'", warnlen, warn);
  23        }
  24        return o;
  25}
  26
  27struct object *deref_tag_noverify(struct object *o)
  28{
  29        while (o && o->type == OBJ_TAG) {
  30                o = parse_object(o->sha1);
  31                if (o && o->type == OBJ_TAG && ((struct tag *)o)->tagged)
  32                        o = ((struct tag *)o)->tagged;
  33                else
  34                        o = NULL;
  35        }
  36        return o;
  37}
  38
  39struct tag *lookup_tag(const unsigned char *sha1)
  40{
  41        struct object *obj = lookup_object(sha1);
  42        if (!obj)
  43                return create_object(sha1, OBJ_TAG, alloc_tag_node());
  44        if (!obj->type)
  45                obj->type = OBJ_TAG;
  46        if (obj->type != OBJ_TAG) {
  47                error("Object %s is a %s, not a tag",
  48                      sha1_to_hex(sha1), typename(obj->type));
  49                return NULL;
  50        }
  51        return (struct tag *) obj;
  52}
  53
  54static unsigned long parse_tag_date(const char *buf, const char *tail)
  55{
  56        const char *dateptr;
  57
  58        while (buf < tail && *buf++ != '>')
  59                /* nada */;
  60        if (buf >= tail)
  61                return 0;
  62        dateptr = buf;
  63        while (buf < tail && *buf++ != '\n')
  64                /* nada */;
  65        if (buf >= tail)
  66                return 0;
  67        /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
  68        return strtoul(dateptr, NULL, 10);
  69}
  70
  71int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
  72{
  73        unsigned char sha1[20];
  74        char type[20];
  75        const char *bufptr = data;
  76        const char *tail = bufptr + size;
  77        const char *nl;
  78
  79        if (item->object.parsed)
  80                return 0;
  81        item->object.parsed = 1;
  82
  83        if (size < 64)
  84                return -1;
  85        if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
  86                return -1;
  87        bufptr += 48; /* "object " + sha1 + "\n" */
  88
  89        if (prefixcmp(bufptr, "type "))
  90                return -1;
  91        bufptr += 5;
  92        nl = memchr(bufptr, '\n', tail - bufptr);
  93        if (!nl || sizeof(type) <= (nl - bufptr))
  94                return -1;
  95        strncpy(type, bufptr, nl - bufptr);
  96        type[nl - bufptr] = '\0';
  97        bufptr = nl + 1;
  98
  99        if (!strcmp(type, blob_type)) {
 100                item->tagged = &lookup_blob(sha1)->object;
 101        } else if (!strcmp(type, tree_type)) {
 102                item->tagged = &lookup_tree(sha1)->object;
 103        } else if (!strcmp(type, commit_type)) {
 104                item->tagged = &lookup_commit(sha1)->object;
 105        } else if (!strcmp(type, tag_type)) {
 106                item->tagged = &lookup_tag(sha1)->object;
 107        } else {
 108                error("Unknown type %s", type);
 109                item->tagged = NULL;
 110        }
 111
 112        if (bufptr + 4 < tail && !prefixcmp(bufptr, "tag "))
 113                ;               /* good */
 114        else
 115                return -1;
 116        bufptr += 4;
 117        nl = memchr(bufptr, '\n', tail - bufptr);
 118        if (!nl)
 119                return -1;
 120        item->tag = xmemdupz(bufptr, nl - bufptr);
 121        bufptr = nl + 1;
 122
 123        if (bufptr + 7 < tail && !prefixcmp(bufptr, "tagger "))
 124                item->date = parse_tag_date(bufptr, tail);
 125        else
 126                item->date = 0;
 127
 128        return 0;
 129}
 130
 131int parse_tag(struct tag *item)
 132{
 133        enum object_type type;
 134        void *data;
 135        unsigned long size;
 136        int ret;
 137
 138        if (item->object.parsed)
 139                return 0;
 140        data = read_sha1_file(item->object.sha1, &type, &size);
 141        if (!data)
 142                return error("Could not read %s",
 143                             sha1_to_hex(item->object.sha1));
 144        if (type != OBJ_TAG) {
 145                free(data);
 146                return error("Object %s not a tag",
 147                             sha1_to_hex(item->object.sha1));
 148        }
 149        ret = parse_tag_buffer(item, data, size);
 150        free(data);
 151        return ret;
 152}
 153
 154/*
 155 * Look at a signed tag object, and return the offset where
 156 * the embedded detached signature begins, or the end of the
 157 * data when there is no such signature.
 158 */
 159size_t parse_signature(const char *buf, unsigned long size)
 160{
 161        char *eol;
 162        size_t len = 0;
 163        while (len < size && prefixcmp(buf + len, PGP_SIGNATURE) &&
 164                        prefixcmp(buf + len, PGP_MESSAGE)) {
 165                eol = memchr(buf + len, '\n', size - len);
 166                len += eol ? eol - (buf + len) + 1 : size - len;
 167        }
 168        return len;
 169}